From: Tim Newsham <newsham@lava.net>
To: Sergey Reva <rs_rlab@mail.ru>,
Fans of the OS Plan 9 from Bell Labs <9fans@cse.psu.edu>
Subject: Re: [9fans] How it work?
Date: Tue, 22 Mar 2005 14:40:17 -1000 [thread overview]
Message-ID: <Pine.BSI.4.61.0503221431500.25349@malasada.lava.net> (raw)
In-Reply-To: <16725440859.20050322210023@mail.ru>
> I try understand synchronization in Plan 9.
> I find test-and-set routines (for PC) in l.s, but I can't find where
> it used. Also I can't find any reason why it unused... so where it used?
The kernel's files are spread out over /sys/src/9/{pc,port,ip}.
Take a look at port/{qlock,taslock}.c.
> And why rendezvous is syscall, but lock, qlock are library routines
> which look like the same as kernel qlock.c
There are several types of locks. Some (like spin locks) can operate
without any assistance from the kernel (not entirely, they yield with a
syscall). Others (like rendezvous) use the kernel to mediate between the
processes. The lock(2) man page has more details.
Tim N.
next prev parent reply other threads:[~2005-03-23 0:40 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2005-03-22 19:00 Sergey Reva
2005-03-23 0:40 ` Tim Newsham [this message]
2005-03-23 6:57 ` Sergey Reva
2005-03-23 17:34 ` Russ Cox
2005-03-24 8:46 ` Sergey Reva
2005-03-24 8:55 ` noselasd
[not found] ` <4439b95e268ad4987f174271ac554f28@smtp.songnetworks.no>
2005-03-25 10:33 ` Sergey Reva
2005-03-25 17:08 ` Russ Cox
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